The QPointF class defines a point in the plane using floating point precision. More...
| Header: | #include <QPointF> |
| CMake: | find_package(Qt6 COMPONENTS Core REQUIRED) target_link_libraries(mytarget PRIVATE Qt6::Core) |
| qmake: | QT += core |
Note: All functions in this class are reentrant.
| QPointF(qreal xpos, qreal ypos) | |
| QPointF(const QPoint &point) | |
| QPointF() | |
| bool | isNull() const |
| qreal | manhattanLength() const |
| qreal & | rx() |
| qreal & | ry() |
| void | setX(qreal x) |
| void | setY(qreal y) |
| CGPoint | toCGPoint() const |
| QPoint | toPoint() const |
| QPointF | transposed() const |
| qreal | x() const |
| qreal | y() const |
| QPointF & | operator*=(qreal factor) |
| QPointF & | operator+=(const QPointF &point) |
| QPointF & | operator-=(const QPointF &point) |
| QPointF & | operator/=(qreal divisor) |
| qreal | dotProduct(const QPointF &p1, const QPointF &p2) |
| QPointF | fromCGPoint(CGPoint point) |
| bool | operator!=(const QPointF &p1, const QPointF &p2) |
| QPointF | operator*(const QPointF &point, qreal factor) |
| QPointF | operator*(qreal factor, const QPointF &point) |
| QPointF | operator+(const QPointF &p1, const QPointF &p2) |
| QPointF | operator+(const QPointF &point) |
| QPointF | operator-(const QPointF &p1, const QPointF &p2) |
| QPointF | operator-(const QPointF &point) |
| QPointF | operator/(const QPointF &point, qreal divisor) |
| QDataStream & | operator<<(QDataStream &stream, const QPointF &point) |
| bool | operator==(const QPointF &p1, const QPointF &p2) |
| QDataStream & | operator>>(QDataStream &stream, QPointF &point) |
A point is specified by a x coordinate and an y coordinate which can be accessed using the x() and y() functions. The coordinates of the point are specified using finite floating point numbers for accuracy. The isNull() function returns true if both x and y are set to 0.0. The coordinates can be set (or altered) using the setX() and setY() functions, or alternatively the rx() and ry() functions which return references to the coordinates (allowing direct manipulation).
Given a point p, the following statements are all equivalent:
QPointF p; p.setX(p.x() + 1.0); p += QPointF(1.0, 0.0); p.rx()++;
A QPointF object can also be used as a vector: Addition and subtraction are defined as for vectors (each component is added separately). A QPointF object can also be divided or multiplied by an int or a qreal.
In addition, the QPointF class provides a constructor converting a QPoint object into a QPointF object, and a corresponding toPoint() function which returns a QPoint copy of this point. Finally, QPointF objects can be streamed as well as compared.
See also QPoint and QPolygonF.
Constructs a point with the given coordinates (xpos, ypos).
Constructs a copy of the given point.
See also toPoint().
Constructs a null point, i.e. with coordinates (0.0, 0.0)
See also isNull().
[static, since 5.1] qreal QPointF::dotProduct(const QPointF &p1, const QPointF &p2)
QPointF p( 3.1, 7.1); QPointF q(-1.0, 4.1); int lengthSquared = QPointF::dotProduct(p, q); // lengthSquared becomes 26.01
Returns the dot product of p1 and p2.
This function was introduced in Qt 5.1.
[static, since 5.8] QPointF QPointF::fromCGPoint(CGPoint point)
Creates a QRectF from CGPoint point.
This function was introduced in Qt 5.8.
See also toCGPoint().
Returns true if both the x and y coordinates are set to 0.0 (ignoring the sign); otherwise returns false.
Returns the sum of the absolute values of x() and y(), traditionally known as the "Manhattan length" of the vector from the origin to the point.
See also QPoint::manhattanLength().
Returns a reference to the x coordinate of this point.
Using a reference makes it possible to directly manipulate x. For example:
QPointF p(1.1, 2.5); p.rx()--; // p becomes (0.1, 2.5)
Returns a reference to the y coordinate of this point.
Using a reference makes it possible to directly manipulate y. For example:
QPointF p(1.1, 2.5); p.ry()++; // p becomes (1.1, 3.5)
Sets the x coordinate of this point to the given finite x coordinate.
Sets the y coordinate of this point to the given finite y coordinate.
[since 5.8] CGPoint QPointF::toCGPoint() const
Creates a CGPoint from a QPointF.
This function was introduced in Qt 5.8.
See also fromCGPoint().
Rounds the coordinates of this point to the nearest integer, and returns a QPoint object with the rounded coordinates.
See also QPointF().
[since 5.14] QPointF QPointF::transposed() const
Returns a point with x and y coordinates exchanged:
QPointF{1.0, 2.0}.transposed() // {2.0, 1.0} This function was introduced in Qt 5.14.
See also x(), y(), setX(), and setY().
Returns the x coordinate of this point.
Returns the y coordinate of this point.
Multiplies this point's coordinates by the given finite factor, and returns a reference to this point. For example:
QPointF p(-1.1, 4.1); p *= 2.5; // p becomes (-2.75, 10.25)
See also operator/=().
Adds the given point to this point and returns a reference to this point. For example:
QPointF p( 3.1, 7.1); QPointF q(-1.0, 4.1); p += q; // p becomes (2.1, 11.2)
See also operator-=().
Subtracts the given point from this point and returns a reference to this point. For example:
QPointF p( 3.1, 7.1); QPointF q(-1.0, 4.1); p -= q; // p becomes (4.1, 3.0)
See also operator+=().
Divides both x and y by the given divisor, and returns a reference to this point. For example:
QPointF p(-2.75, 10.25); p /= 2.5; // p becomes (-1.1, 4.1)
The divisor must not be zero or NaN.
See also operator*=().
Returns true if p1 is sufficiently different from p2; otherwise returns false.
Warning: This function does not check for strict inequality; instead, it uses a fuzzy comparison to compare the points' coordinates.
See also qFuzzyCompare.
Returns a copy of the given point, multiplied by the given finite factor.
See also QPointF::operator*=().
This is an overloaded function.
Returns a copy of the given point, multiplied by the given finite factor.
Returns a QPointF object that is the sum of the given points, p1 and p2; each component is added separately.
See also QPointF::operator+=().
[since 5.0] QPointF operator+(const QPointF &point)
Returns point unmodified.
This function was introduced in Qt 5.0.
Returns a QPointF object that is formed by subtracting p2 from p1; each component is subtracted separately.
See also QPointF::operator-=().
This is an overloaded function.
Returns a QPointF object that is formed by changing the sign of each component of the given point.
Equivalent to QPointF(0,0) - point.
Returns the QPointF object formed by dividing each component of the given point by the given divisor.
The divisor must not be zero or NaN.
See also QPointF::operator/=().
Writes the given point to the given stream and returns a reference to the stream.
See also Serializing Qt Data Types.
Returns true if p1 is approximately equal to p2; otherwise returns false.
Warning: This function does not check for strict equality; instead, it uses a fuzzy comparison to compare the points' coordinates.
See also qFuzzyCompare.
Reads a point from the given stream into the given point and returns a reference to the stream.
See also Serializing Qt Data Types.
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Licensed under the GNU Free Documentation License, Version 1.3.
https://doc.qt.io/qt-6.2/qpointf.html